‘47 rear brake cylinder question

[AnthonyG]

Hi all, started putting used rear ‘47 brake backing plates on my ‘35, part of the Hydraulic conversion, & decided to change the rear cylinders before installing. I see the cylinders for a car are significantly more expensive by a factor of 5 than for a pickup? I’m cheap LOL so can the car brake cylinders b swapped out for the less expensive PU truck cylinders? $20 vs $120